Explain Differentials To Me

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ZacUnknown69

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Alright - as we all know, the Mark had either a 3.08 or 3.27, and if you ask me that's lame. So apart from my mad ideas of supercharging, or turbocharging my Mark. Here's something I might actually be able to do. I want to swap out the stock differential with a limited-slip 4.10! But - I'm not doing the gears myself. I'd prefer just to buy the whole package in one deal (housing, differential). Since I'm useless on this specific subject; I've found something (link below) with that can I just open up the differential, install that and everything is well? Boom, 4.10/LSD? What is all involved? How long does it take? What kind of performance increase will I see? And if the product I've shown won't work, please, post a link of one that will. Thank you!

http://www.cjponyparts.com/ford-rac...zy4jRa-WUEVip1Sf9xPj44GWM8NWMaBbRMaAnDQ8P8HAQ
 
You'll see exactly zero performance increase. Your link is to a locking differential. You reuse the gearset you already have, so whatever ratio you have now is the ratio you'll have after you install this.
 
buy ford racing 4.10 gears and a 28 spline 8.8 track lock. they are out of production so you'll need to find NOS or a used unit. an install kit is about 100 bucks and install labor is about 400-600 bucks around here.
 
ZacUnknown69 said:
Alright - as we all know, the Mark had either a 3.08 or 3.27, and if you ask me that's lame. So apart from my mad ideas of supercharging, or turbocharging my Mark. Here's something I might actually be able to do. I want to swap out the stock differential with a limited-slip 4.10! But - I'm not doing the gears myself. I'd prefer just to buy the whole package in one deal (housing, differential). Since I'm useless on this specific subject; I've found something (link below) with that can I just open up the differential, install that and everything is well? Boom, 4.10/LSD? What is all involved? How long does it take? What kind of performance increase will I see? And if the product I've shown won't work, please, post a link of one that will. Thank you!

Ford Racing M-4204-M Mustang Differential 8.8" GT 2015-2017
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When the gear ratio numbers go hi the gas millage goes low. They were built for hi mpg's so they lowered the rear end number. Just know the 4.1 will make the motor run faster but good speed up to 80 and then it will not have top end speed
 
Rockbottom said:
Just know the 4.1 will make the motor run faster but good speed up to 80 and then it will not have top end speed
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no top speed with 4.10s my ass.
31777449044_37490fa7a6_b.jpg
IMG00489-20120315-0016 by Chris Bratten, on Flickr
 
chris2523 said:
no top speed with 4.10s my ass.
View attachment 828486560IMG00489-20120315-0016 by Chris Bratten, on Flickr
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chris2523 said:
no top speed with 4.10s my ass.
View attachment 828486560IMG00489-20120315-0016 by Chris Bratten, on Flickr
Click to expand...
The picture of the 140 mph at 5,000 revs indicates you were not running a 4.1 ratio gear. . The mechanics are when the engine is turning over 1 revolution, the wheels (back or front) would make 1 revolution. Thats a 1 to 1 ratio. But when the rear end gears are changed to a 3.0 for example the motor does 3 revolutions for the wheel to do 1. The higher the rear end ratio numericaly, 4.0 5.0, the faster the motor must run. Marks have an over drive which would allow a hi number rear end to become a lower number rear end thus allowing for more top speed than a non overdrive transmission. For you to reach the speed doing just 5.000 + rpm your transmission was a 4 speed. . Had you had stock rear end the car can reach the 170 mph .A direct drive ratio could let a car go as fast as the rpms of the motor.. Very hard to get it moving though. Its not hard to figure what the real final ratio would be thru the 4 th gear of your 4.1 rear. The higher the rear the faster the engine runs, the lower rear, the more top speed and lower rpms the motor can run.
 
Rockbottom said:
The picture of the 140 mph at 5,000 revs indicates you were not running a 4.1 ratio gear. . The mechanics are when the engine is turning over 1 revolution, the wheels (back or front) would make 1 revolution. Thats a 1 to 1 ratio. But when the rear end gears are changed to a 3.0 for example the motor does 3 revolutions for the wheel to do 1. The higher the rear end ratio numericaly, 4.0 5.0, the faster the motor must run. Marks have an over drive which would allow a hi number rear end to become a lower number rear end thus allowing for more top speed than a non overdrive transmission. For you to reach the speed doing just 5.000 + rpm your transmission was a 4 speed. . Had you had stock rear end the car can reach the 170 mph .A direct drive ratio could let a car go as fast as the rpms of the motor.. Very hard to get it moving though. Its not hard to figure what the real final ratio would be thru the 4 th gear of your 4.1 rear. The higher the rear the faster the engine runs, the lower rear, the more top speed and lower rpms the motor can run.
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I think you're forgetting the 4R70W has a 0.7 ratio overdrive. Yes you can run 4.10s at 140 mph doing a bit over 5000 rpms.
 
driller said:
I think you're forgetting the 4R70W has a 0.7 ratio overdrive. Yes you can run 4.10s at 140 mph doing a bit over 5000 rpms.
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The overdrive is the reason th4.1 could run 5 k @ 140. Read over . High number rear end , as a chevy 4.70 makes the mill work hard provided no overdrive
 
Rockbottom said:
The overdrive is the reason th4.1 could run 5 k @ 140. Read over . High number rear end , as a chevy 4.70 makes the mill work hard provided no overdrive
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Incomprehensible. There are reasons high value people seldom post here.

Did you know that Lincoln stripped off the mirrors, and took a 93 Mark to Bonneville? It did about 183 mph, as I remember.
 
Any motor has to turn over more rpms when a hi gear ratio rear end is switched for a low ratio rear end. A high ratio rear end gear allows faster acceleration from a standing start but without the 4th gear overdrive, the top speed will be less because the engine is wound out quickly. A 4.1 rear end ratio means the motor is running 4 revolutions for every 1 turn of the rear tire. I have had cars with as low as a 2.96 and a 3.55 rear end ratios. They allowed great top end and they were not overdrives. Notice the stock mark 8 will run at 2500 rpm while the car is doing 70-75 mph. Thats how they get great gas millage along with the small 281 cubic inch motor .
 
PenGun said:
Incomprehensible. There are reasons high value people seldom post here.

Did you know that Lincoln stripped off the mirrors, and took a 93 Mark to Bonneville? It did about 183 mph, as I remember.
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This mark was running a 2.47rear end ratio which allowed their motor to run less rpms and reach a higher 2 way average 181.717 mph .with a ford modified automatic by disabling 4th gear . Car ran the course in 3r gear.Yes, that 2.47 ratio slowed the 281 cubic inch down while allowing for more mile per hour top end speed. Take that in your pipe and smoke it
 
Rockbottom said:
This mark was running a 2.47rear end ratio which allowed their motor to run less rpms and reach a higher 2 way average 181.717 mph .with a ford modified automatic by disabling 4th gear . Car ran the course in 3r gear.Yes, that 2.47 ratio slowed the 281 cubic inch down while allowing for more mile per hour top end speed. Take that in your pipe and smoke it
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Ah, you can use google, perhaps there's hope.
 
PenGun said:
Incomprehensible. There are reasons high value people seldom post here.

Did you know that Lincoln stripped off the mirrors, and took a 93 Mark to Bonneville? It did about 183 mph, as I remember.
Click to expand...
Rockbottom said:
The picture of the 140 mph at 5,000 revs indicates you were not running a 4.1 ratio gear. . The mechanics are when the engine is turning over 1 revolution, the wheels (back or front) would make 1 revolution. Thats a 1 to 1 ratio. But when the rear end gears are changed to a 3.0 for example the motor does 3 revolutions for the wheel to do 1. The higher the rear end ratio numericaly, 4.0 5.0, the faster the motor must run. Marks have an over drive which would allow a hi number rear end to become a lower number rear end thus allowing for more top speed than a non overdrive transmission. For you to reach the speed doing just 5.000 + rpm your transmission was a 4 speed. . Had you had stock rear end the car can reach the 170 mph .A direct drive ratio could let a car go as fast as the rpms of the motor.. Very hard to get it moving though. Its not hard to figure what the real final ratio would be thru the 4 th gear of your 4.1 rear. The higher the rear the faster the engine runs, the lower rear, the more top speed and lower rpms the motor can run.
Click to expand...
 
PenGun said:
Ah, you can use google, perhaps there's hope.
Click to expand...
Well its a 2.47 rear end and you couldn't understand the logic . The mark set a record using a 2.47 rear end of 181.717, A low number ratio increases the top end speed. Incomprehensible, your not as dumb as you sound.
 
Rockbottom said:
Well its a 2.47 rear end and you couldn't understand the logic . The mark set a record using a 2.47 rear end of 181.717, A low number ratio increases the top end speed. Incomprehensible, your not as dumb as you sound.
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I used to have a 69 Cutlass with a 502 in it, I left the stock ratio in it, I think a 3.08 or something. It would theoretically go 180 or so, but lifted off around 160.

I built it to crush 5 liter fords, a long time ago. They were so aggressive and would pick on my rather scrappy looking car, although strangely wheeled, tired and hung, if one looked. At 70 mph where I liked to start the party, I could drop it into second, and make smoke. A hundred arrived quite quickly and then the 5 liter would have usually given up.
 
If you were closer to me i would've helped you with the diff. Its not that bad of a job if you're mechanically inclined and a decent dial indicator with a stand is under $100. Thats really the only speciality tool you would need other than a good air compressor and impact for the crush sleeve. I'll be swapping in a 4:10 gearset in my 98 soon along with a carbon clutch pack so how do you like the new gears in yours? You can still drive on the interstate fast as you want to go?

29-1_zpsff9xmndv.jpg


28-1_zps7jwr8iy5.jpg
 
Rockbottom said:
The picture of the 140 mph at 5,000 revs indicates you were not running a 4.1 ratio gear. .
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i built the diff. i know what was used.


Dr.Mark said:
I'll be swapping in a 4:10 gearset in my 98 soon along with a carbon clutch pack so how do you like the new gears in yours? You can still drive on the interstate fast as you want to go?
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do it, i have no regrets. i also have the carbon clutch pack.
 
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